The figure shows a pendulum of length
′I′ suspended at a distance
x vertically above a peg. The pendulum bob is deflected through an angle
θ and then released. When
θ=90∘, the pendulum complete the circle. When
θ=60∘ the velocity of the bob as it passes position
E is
√kl. Find the value of
k(g=10 m/sec2).